1. Field of the Invention
The present invention relates to an adsorbing capacity determining system in an exhaust emission control unit for an internal combustion engine in which an unburned component adsorbing means is provided for temporarily adsorbing an unburned component in the exhaust gas from the engine.
2. Description of the Prior Art
An exhaust emission control unit is conventionally known, for example, as in Japanese Utility Model Application Laid-open No. 105925/92. The exhaust emission control unit includes an unburned component adsorbing means provided in an exhaust system for temporarily adsorbing an unburned component in the exhaust gas in order to prevent the unburned component from being released to the atmosphere when an exhaust emission control catalyst is inactivated during a cold start of an internal combustion engine or at other times.
The unburned component adsorbing means is constructed using granular activated carbon or zeolite and adsorbs an unburned component of the exhaust gas comprising hydrocarbon(s). When the capacity for adsorbing the unburned component is reduced due to a secular change or the like, there is a possibility that the unburned component is directly released into the atmosphere without adsorption.